I found this some time ago, this is still one of my favorite things. It's original, beautiful, funny, poetic, intriguing, even sad at some points (the fact that there's an entire section for undelivered letters in the library got me...and the memorials...). There's no way we could ever fully explain the TARDIS with hard science, so I love this approach better. A little bit of science, a little bit of magic. I'm sure that's how Gallifreyan technology would look like to us humans, anyway :)

Hopefully the PDF link would get updated someday (or does anybody else still has a copy?...)